Plasma concentration profiles of ribavirin were studied after the first dose (D0) and at W12. At each period, blood samples were collected pre-dose and 30 minutes, 1, 1.5, 2, 3, 4, 6, 8, and 10 hours post-dosing. Ribavirin concentrations were measured using liquid chromatography-tandem mass spectrometry and ribavirin area under the concentration-timcurves (AUC0-10h) were derived from plasma concentrations profiles using the linear trapezoidal rule.